Eagle QuickTip: Teardrops

If you have to work on a particularly dense board, you can’t really get away from using small vias: <=0.3mm/12mil drill bits and <=0.125mm/5mil annular rings.  While unavoidable, using small vias and particularly small annular rings poses a problem during manufacturing, since there is inevitably some variability with the drill placement and the smaller the annular rings (the metal ring left around the drilled hole) the more likely you are to end up with a broken via.  One easy solution to improve your yield of error-free boards is using something called ‘teardrops’.  They fan the trace out before it joins the via, making a ‘teardrop’ shape, effectively increasing the size of the annular ring and reducing the risk of faulty vias.

Most packages include some means to create teardrops, and Eagle is no exception.  The default installation includes a ULP called ‘teardrops.ulp’, which you can run by simply typing ‘ULP teardrop’ when your board file is open.  One word of caution, though … you should only run the teardrop ULP on a seperate, renamed copy of your board file since the changes are irreversable!.  Make a copy of your board names xxx_teardrops.brd, make sure the original schematic is closed, and then run “ULP teardrop”.  Give it a try and you should get an idea of why they can be useful on tight-pitch boards like the image above, which was from a 6mil/6mil 4-layer board with 0.3mm drill holes and 0.1mm annulars.


Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Join 35,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org

Maker Business — Chip inventories rise as demand falls

Wearables — How to attach a battery to your next wearables project

Electronics — Check out this shorthand shortcut

Python for Microcontrollers — Python on Microcontrollers Newsletter: 400 CircuitPython Libraries, 3m Thanks and much more! #CircuitPython #Python @ThePSF @micropython @Raspberry_Pi

Adafruit IoT Monthly — 2022 in Recap!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — JP’s Product Pick of the Week 1/24/23 IoT Button BFF w NeoPixel for QT Py @adafruit @johnedgarpark #adafruit #newproductpick

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !

1 Comment

  1. This is very useful information. Please keep the tips coming!

Sorry, the comment form is closed at this time.